Presenter: Fernanda B. O. Santos
Advisor(s): Brian W. Sheldon and
Peter R. Ferket
Author(s): Fernanda B. O. Santos, Brian W. Sheldon and Peter R. Ferket
Graduate Program:
Poultry Science

Title: Impact of poultry age, season, litter quality, and nutritional intervention strategies on Salmonella prevalence and populations, serotypes, genotypes, and antibiotic resistance profiles

Abstract: Poultry-related salmonellosis is an on-going problem that the poultry industry must continue to address. To address these challenges, our research objectives were to first assess Salmonella populations present on brooder and grow-out turkey farms (litter and fecal samples) using a quantitative procedure; investigate the diversity of Salmonella serotypes present on these farms using serotyping, genotyping by pulsed-field gel electrophoresis and antibiotic resistance-susceptibility analyses. Additionally, alternative on-farm pathogen intervention strategies including feeding whole grains, increasing insoluble fiber content and use of an alternative cage-based housing design (Broilermatic System®) were evaluated. Salmonella litter populations averaged 2 logs higher in 3-wk turkey samples compared to samples from 19-wk birds (4.1 vs. 2.1 log/g, P=0.002). Turkey age also influenced Salmonella serotypes, genotypes and antibiotic resistance profiles. Only 2 Salmonella serotypes (Javaina and Mbandaka) were common between 3 and 19-wk turkeys. Isolates from 3-wk birds were resistant to >4 drugs and those from 19-wk were resistant to <3 antibiotics (P=0.027). Supplementing coarse ground corn and increased insoluble fiber (wood fiber) content into the turkey diet did not adversely impact body weights. However, the treatments did not influence Salmonella colonization or fecal shedding from turkeys. To examine the impact of housing design and addition of whole grains (whole triticale and coarse ground corn), broilers were reared on these supplemented diets to market age and Salmonella colonization measured. Whole grain supplementation decreased Salmonella cecal populations (5.3 vs. 6.5 log/g, whole triticale vs. ground corn at 28-d, P=0.0028) while rearing broilers on floor litter as opposed to the Broilermatic® resulted in significant reductions in Salmonella contamination (5.5 vs. 6.2 log/g at 28-d, P=0.0007). In conclusion, highly variable Salmonella populations and serotypes were detected across all commercial turkey farms and the use of alternative feed ingredients such as triticale may help in decreasing Salmonella colonization in poultry.